[Effect of Staphylococcal Nuclease and Tudor Domain Containing 1/SLC7A11 on the Occurrence and Development of Osteosarcoma by Inhibiting Ferroptosis]

Objective To investigate the effect of staphylococcal nuclease and tudor domain containing 1(SND1) on the biological function of osteosarcoma cells and decipher the mechanism of SND1 in regulating ferroptosis in osteosarcoma cells via SLC7A11. Methods Human osteoblasts hFOB1.19 and osteosarcoma cell lines Saos-2,U2OS,HOS,and 143B were cultured,in which the expression level of SND1 was determined.Small interfering RNA was employed to knock down the expression of SND1(si-SND1) in the osteosarcoma cell line HOS and 143B.The CCK8 assay kit,colony formation assay,and Transwell assay were employed to examine the effect of SND1 expression on the biological function of osteosarcoma cells.Furthermore,we altered the expression of SND1 and SLC7A11 in osteosarcoma cells to investigate the effect of SND1 on osteosarcoma ferroptosis via SLC7A11. Results The mRNA and protein levels of SND1 in Saos-2,U2OS,HOS,and 143B cells were higher than those in hFOB1.19 cells(all P<0.01).Compared with the control group,transfection with si-SND1 down-regulated the expression level of SND1 in HOS and 143B cells(all P<0.01),decreased the viability of HOS and 143B cells,reduced the number of colony formation,and inhibited cell invasion and migration(all P<0.001).The ferroptosis inducer Erastin promoted the apoptosis of HOS and 143B cells,while the ferroptosis inhibitor Ferrostatin-1 improved the viability of HOS and 143B cells(all P<0.001).After SND-1 knockdown,Erastin reduced the viability of HOS and 143B cells,while Ferrostatin-1 restored the cell viability(all P<0.001).After treatment with Erastin in the si-SND1 group,the levels of iron and malondialdehyde were elevated,and the level of glutathione was lowered(all P<0.001).The results of in vivo experiments showed that SND1 knockdown inhibited the mass of the transplanted tumor in 143B tumor-bearing nude mice(P<0.001).Knocking down the expression of SND1 resulted in down-regulated SLC7A11 expression(all P<0.001) and increased ferroptosis in HOS and 143B cells(P<0.001,P=0.020). Conclusions SND1 presents up-regulated expression in osteosarcoma cells.It may inhibit ferroptosis by up-regulating the expression of SLC7A11,thereby improving the viability of osteosarcoma cells.

[Treatment choices for infected pancreatic necrosis:surgery debridement or endoscopy drainage?]

Infected pancreatic necrosis (IPN) is a crucial reason for the poor prognosis of patients with acute pancreatitis,which is complicated and difficult to predict the outcomes. Surgery is an important way to cure IPN,and "step-up approach" is the mainstream mode of IPN treatment. In the era of minimally invasive surgery,the full course endoscopic treatment of IPN has been gradually hot and achieved good outcomes as endoscopic technology' improvement. However,it is controversial that whether technique is better for IPN by surgery debridement or endoscopy drainage,and there is no consensus on the scope of applicability and the timing of intervention. The paper aims to explore the intervention methods,indications and timing of endoscopic and surgical treatment of IPN and elaborate the selection strategies of them in clinical practice,so as to develop individualized treatment options,accurately implement minimally invasive intervention and improve the prognosis.

[Rethinking on the classification of infected pancreatic necrosis and its surgical intervention strategy]

Infected pancreatic necrosis is a complex disease which is difficult to deal with.Timely and effective removal of the infection is the core of surgical treatment.Accurate determination and location of the infected area as well as targeted drainage and debridement are the key to further enhance the overall cure rate of necrotizing pancreatitis.Combining the clinical practice and relevant literatures,the classification of infected pancreatic necrosis is tentatively proposed based on the site of infection and necrosis or treatment in this paper.Meanwhile, the diversified intervention methods in the new era and the issues that need attention in the concept of step-up approach are rediscussed, aiming at scientific planning of treatment strategies and targeted intervention methods to reduce patients' mortality and improve prognosis.

A study on pathogenicity of hepatitis G virus

AIM: To study the pathogenicity of hepatitis G virus (HGV) and observe the genesis and pathological process of hepatitis G.

METHODS: HGV-RNA in serum was detected by RT-PCR assay. The immunohistochemical assays of liver tissue were performed with HGV monocoloned antibody (McAb) expressed from the region of HGV NS5 nucleic acid sequence. The clinical and pathological data of 52 patients with hepatitis G were discussed. In animal experiment, the Chinese Rhesus monkeys were infected with the serum of a patient with HGV infection. And the dynamic changes in serology and liver histology of animals were observed.

RESULTS: One hundred and fifty-four patients with HGV-RNA positive were selected from 1552 patients with various kinds of hepatitis. Of 154 patients with HGV infection, 52 were infected with HGV only, which accounted for 33.8% (52/154) and 102 with positive HGV-RNA were super-infected with other hepatitis viruses, which accounted for 66.2% (102/154). The clinical and pathological observation showed that the acute and chronic hepatitis could be induced by HGV. The slight abnormality of transaminases ALT and AST in serum of monkeys lasted nearly 12 months and histological results showed a series of pathological changes.

CONCLUSION: HGV is a hepatotropic virus and has pathogenicty.